Furnace for kilns.



N0. 653,89l. Paient'ed .Iuly I7, I900. F. B. SELLMAN.

FURNACE FOR KILNS.

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No. 653,891. Patented July 17, I900. F. R. SELLMAN.

FURNACE FUR KILNS.

(Application filed May 15, 1900.) (No Model.) 4 Sheets-Sheet 2 "m5 NORRIG FEIERS cu. mcrauma, WASHINGTON, n. c,

Patented July l7, I900.

F. R. SELLMAN.

FURNACE FOR KILNS.

(Applicatibn filed May 15, 1900.)

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Patented July [7, I900. F. B. SELLMAN.

FURNACE FUR KILNS.

(Application filed my 15, 1900.;

Sheet 4,

4'Sheets (No Model.)

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NITED STATES FREDERICK R. SELLMAN,

OF ST. LOUIS, MISSOURI.

FURNACE FOR KIVLNFS.

SPECIFICATION forming part of Letters Patent No. 653,891, dated July 17, 1906.

Original application filed December 23, 1899, Serial No- 741,423; Divided and this application filed May 15, 1900. Serial No; 16,781. on model.)

To ctZZ whom it may concern:

Be it known thatl, FREDERIOKR. SELLMAN, a citizen of the United States, residing at the city of St. Louis, in the State of Missouri, have invented a certain new and useful Improvement in Furnaces for Kilns, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the acompanying drawings, forming part of this specification.

This invention relates to a new and useful improvement in furnaces, being shown in the drawings as operative in connection with kilns; but I do not wish to confine myself to the class of devices with which my improved furnace cooperates, as there are various uses to which the same may be put without in the least departing from the nature and principle of my invention.

The object of my invention is to construct a furnace in a simple and economical manner and to so arrange the several parts constitnting the same that a great saving in fuel will result, the furnace at all times maintaining the highest efficiency.

The subject-matter of this present application has been divided from an application for improvements in furnaces filed by me on or about December 23, 1899, serially numbered 741,428.

In the accompanying drawings I have illustrated a construction resembling in all respects the construction of the furnace shown in my former application-that is, there is a firing chamber into which the fuel to be burned is placed and in which firing-chainber said fuel is consumed by slow stages, only sufficient oxygen being admitted to said chamber to maintain combustion in the lower portion thereof, the heat of the burning fuel in the lower portion of the chamber rising and decomposing or driving off the volatile products of combustion from the green fuel, which is fed on top. This green fuel by this operation is coked, so that when it gradually works its way toward the bottom of the firechamber it reaches a point where the oxygen admitted to support combustion is sufficient to burn said coke, the green fuel being constantly introduced on top and in the upper portion of the fire-chamber to maintain the depth of the bed of fuel and giving out its volatile products of combustion, as above stated. In order to maintain the burning fuel, say, at a red heat, steam is generated in juxtaposition thereto, as will hereinafter be described. The volatile products of combustion resulting from the decomposition of the gases in the green fuel pass from the firechamber into what I will term the mixingchamber, into which mixing-chamber is admitted hot air. The gases and hot air being thoroughly mixed by an appropriate device then pass into a combustion-chamber, which is shown in the drawings as being located in the upper portion of a kiln, wherein combustion takes place, the products of combustion passing downwardly through and around the articles to be annealed, burned, or otherwise treated in the kiln into and through a suitable passage-way leading to a stack or other exit or escape.

The above is a brief description of the operation of the furnace.

The features of invention which are claimed in this application reside in the construction, arrangement, and combination of the several parts, all as will hereinafter be described and afterward pointed out in the claims. I attain these objects by the mechanism illustrated in the accompanying drawings, in which Figure 1 is a transverse vertical sectional view of my improved furnace. Fig. 2 is a longitudinal verticalsectional View of the furnace, the same beingindicated by the line 2 2 of Figs. 1 and 3. Fig. 3 is a front elevational view of the central portion of my improved furnace, a portion of the walls,flooring, and ceiling of the pit below the surface of the ground being shown in section. Fig.

4: is a perspective view of a portion of my imv proved furnace and its ovens or kilns. Fig. 5 is a horizontal sectional View of a portion of my improved furnace, the same being taken on the line 5 5 of Fig. 1. Fig. dis a detail perspective view of one of the end tilings of the arched top of the oven or kiln which is employed in carrying out my invention. Fig. 7 is a detail perspective view of one of the arch-supporting tiles employed in carrying out my invention. Fig. 8 is a detail perspective view of one of the tiles upon which the arch-supporting tile illustrated in Fig. 7 rests. Fig. 9 is a detail perspective view of a group of tiling which is utilized in carrying out my invention, the same when properly assembled in the furnace supplying the perforated arched covering for the furnace proper. Fig. 10 is in part a rear elevational view, on a reduced scale, of my improved furnace and in part a sectional view of the fines leading from said furnace. Fig. 11 is a horizontal sectional view, on a reduced scale, of my improved furnace, the same being taken on line 11 11 of Fig. 1. Fig. 12 is a vertical sectional view, on a reduced scale, of my improved furnace, the same being taken on line 12 12, Fig. 1. Fig. 13 is a vertical sectional view, on a reduced scale, of my improved furnace, the same being taken on line 13 13 of Fig. 1; and Fig. 14: is a detail horizontal sectional view of a portion of my improved furnace, the same being taken on line 14. 14 of Fig. 1.

Similar letters refer to similar parts through out the several views.

In the drawings, A indicates a firing-chamber, into the upper portion of which leads a charging-opening a, closed by a door a, said firing-chamber being preferably formed of suitable masonry, so that the walls thereof converge toward the lower portion, at which point are arranged grate-bars B, suitably supported above an ash-pit O.

0 represents a closure for the lower portion of the firing-chamber, which in normal operation of the furnace is closed, so as to exclude the admission of air at this point through this opening, and through which access may be had to the ash-pitC.

The roof of the firing-chamber is preferably arched, as shown in Fig. 1, said roof consisting of oppositely-placed tiles D, (shown in detail in Fig. 9,) the lower bearing-face of said tiles being supported by the side walls of the firing-chamber, while the inner upper edges are cutaway, as at d, to form openings for the passage of the combustible gases from the firing-chamber, one wall (the inner) of said openings being formed by the keystone d, fitted between said tiles, while another wall of said openings is formed by the side face of an adjacent tile. The back faces of tiles D are recessed or cut away at one corner to form passages d", which open laterally at the backs and bottoms of the tiles and upwardly at the tops of said tiles, respectively, as shown more clearly in Fig. 1, which will hereinafter be more particularly referred to.

E indicates what I will term the commingling or mixing chamber,into the bottom of which the openings (1 lead, the side walls 6 of said mixing-chamber being supported on the tops of the tiles -D and being formed of ordinary firebrick, preferably breaking joints with each other, so as to provide openings e through said side walls leading into the mixing-chamber E from a distributing-chamber F, extending practically over the entire back area of each of the walls 6. Distributing-chamber F is formed by a solid back wall f, supported upon a row of tiling G, arranged behind the tiles D. Tiles Gare recessed, as at g, coincident with the recesses 61' and open at their lower ends into a supply-conduit H, extending practically the entire length of the row of recessedtiles G. The bottom wall of conduit H is provided with a series of openings 72., so distributed that the combined areas of said openings equal the total area of available outlet afforded by the passages g to d".

t indicates a closure, preferably in the form of a damper-door, whereby the openings for the admission of air therethrough may be regulated, said air entering a conduit or intake passage I and passing rearwardly and upwardly into a general source of supply for the conduit H through the medium of the openings h, before referred to. The door 11 controls the intake of air to support combustion, said air passing rearwardly through passage I, which, as shown in Fig. 1, is located between the side walls of the fire-chamber and is separated from the escape-conduit for the products of combustion by a thin wall, as will hereinafter be described, so that as said air passes rearwardly through said passage I it is heated, and in passing at the rear end of said passage into the forwardly-extending passage 1 located immediately thereabove, and also between a conduit for the passage of the products of combustion and the wall of the fire-chamber, said air is further heated. The openings 71., which establish communication between the conduit 1 and the chamber H, are such that after the air is heated in the conduits I and I it is forced to distribute itself throughout the entire passage 1 before it is admitted into the passage H, (the opening h being small enough to prevent unequal ad mission of hot air into the chamber H,) and from said chamber H the heated air passes into and through the passages g to c to the general distributing-chamber F, and thence into the mixing-chamber through the openingse'. In this manner the air to support combustion is heated before it enters the mixing-chamber and, being admitted to the mixing-chamber at various points, is readily susceptible of thorough commingling and mixture with the heated gases ascending through the various openings (1.

In order to more thoroughly mix the air and combustible gases in the mixing-chamber E IOC as they pass out of said mixing-chamber, I

take other than a straight passage out of the top of said mixing-chamber. These tiles J support tiles J, whose construction is best shown in Figs. 5 and 7, said tiles J having inwardly-extending tapered projections j in vertical alinement with the pro j eetions j. The upper faces of these projections j support a lintel K, above which is arranged suitable masonry-work k. The body portions of tiles J extend upward to the top of the masonary 7c. The upper outer faces of the tiles J are preferably inclined, and the side faces thereof are formed with ribs J which inclined faces and ribs support tiles L, whose construction is best shown in Fig. 6, said tiles L by reason of their inclined faces forming one of the lateral supports for the arched roof M of the kiln or oven. The inner faces of the tiles L are vertical and form shouldered seats to cooperate with the tiles J and also continue the guideway formed by the rib J and the shoulder of the tapered projection j, in which guideways so formed are fitted dampers N. (See Figs. 1, 2, a, and 5.) These dampers are preferably connected by a bar 0, to which are attached cords 0, passing over sheaves or pulleys mounted on a suitable framework, said dampers being counterbalanced by a weight 0. (See Figs. 2 and 3.)

P indicates the kiln or oven into which the mixed air and gases from the comminglingchamber E are admitted when the dampers N are raised, as shown in Fig. 1.

The floor of the combustion-chamber consists of suitable tiling p, with spaces between them, which are supported by masonry-work q, forming parallel passages Q, leading inwardly to an escape-passage R, which is common to all of said passages Q. The openings of the passages Q into the passage R are restricted, as at *r, (see Figs. 11, 12, and 14,) for the purpose of forcing a general distribution of the escape of the products of combustion from the oven or combustion-chamber. The passage R at its forward end opens downwardly into a passage R, which passage R extends rearwardly and upwardly into a general escape-flue S,which connects with a stack or leads into the eye of an exhaust-fan, as is common. Suitable dampers scontrol the escape of the products of combustion from the passage B into the general escape-flue S.

In starting a fire in the furnace, or if for any reason itis undesirable to have the mixed air and combustible gases enter the combustion-chamber, I provide an escape-flue T, leading from the back of the mixing-chamber E and into the general escape-flue S, the same being controlled by a damper 15, (see Fig. 2,) whose open or closed position renders flue T operative or inoperative, as desired.

In order to support the slow combustion of the bed of fuel in the lower portion of the firing-chamber, I arrange a due U preferably beneath the forward end of the passage R, the volume of air taken through said flue be: ing controlled by a suitable damper u, ar-

ranged in the front end thereof. (See Figs. 3, 11, and 12.) The rear end of flue U connects with the forwardly-extending flue U, arranged, preferably, beneath the passage I, (see Fig. 1,) whose forward end enters the firing-chamber at to. (See Figs. 2 and 11.)

n indicates a supply-pipe through which water is introduced so as to drip onto a pan V, arranged in the open space in front of the firing-chamber for the purpose of generating firing-ohamber or clear the grate-bars of accumulated ashes.

Wherever desired, openings are made in line with the several flues, conduits, or passages, through which may be introduced cleaning devices, said openings serving also as peep-holes. Suitable plugs are employed to close these openings.

In the construction shown in the accompanying drawings the deep bed of fuel is maintained in the firing-chamber, and slow combustion in the lower portion thereof is carried on by the admission of a small quantity of air through the passages U U. The

conditions under which fuel is consumed in this firing-chamber are the same as obtain with respect to ordinary furnaces, with this exception, however, that by reason of the deep bed of fuel combustion is carried on much slower, and consequently is more thorough. the bed is heated, so that it gives up its volatile products, and as it gradually descends it becomes coked and partially incandescent, working its way down to a point where it is near the volume of oxygen admitted to support combustion, when it is finally and thoroughly consumed, leaving but a small quantity of mineral ash. The converging Walls of the firing-chamber serve to concentrate the partially-incandescent fuel, so that a small surface area of grate is necessary. The volatile products, in the form of combustible gases, free carbon, 850., rise into the mixingchamber and are thoroughly commingled with the heated air entering through the intake-passages I I, &c. but by reason of being confined in such a small space as is afforded by the mixing-chamber complete combustion does not take place until the products of the mixing-chamber pass into the combustion chamber or chambers, shown in the drawings as kilns or ovens. roofs of the combustion-chambers form practically an unbroken line, and when the prod The green fuel introduced on top of The lintel and arched 1i esasei ucts from the mixing-chamber enter either of these chambers, which are comparatively large, they are free to expand, so that complete combustion takes place. I will also state that the inlet-opening to the intake-fines I and I, as shown in Fig. 4, being smaller than said fines, admits a small quantity of air, which entering the larger fines is not only permitted to expand under heat, but becomes thoroughly heated before it enters separating the intake and escape flues andv be absorbed by the incoming air, so as to raise the temperature of said incoming air preferably above 800 Fahrenheit or between 800 and 1,200 Fahrenheit. When air heated to this temperature is admitted to the mixing-chamber, it is in condition for immediate combustion when thrown in contact with the combustible gases, so that when the heated air and combustible gases pass from the mixing-chamber into the combustion-chamber they are in a burning state, the large combustion-chamber giving room for expansion during combustion, so that complete combustion results. Retorts, muftles, or other things to be heated in the combustion-chambers are arranged on the perforated floors, with suitable spaces between or around them, and are only built up as high as the wall f, so as to leave ample space under the roof of the oven and above said articles for combustion. The products of combustion pass downwardly through the perforated floor of the oven and into passages Q, R, and R and out through the general escape-flue S. While in passages R R these products of combustion serve to heat the air in the intake-passages I I and U U.

Where a plurality of combustion-chambers are employed in connection with a single fur- 'nace,.the dampers N are used to advantage, in that the several chambers may be fired alternately Without necessitating cessation of the operation of a furnace.

I have found in actual practice that pottery and other articles of similar nature can be burned, annealed, or tempered in the combustion-chambers, such as illustrated in the accompanying drawings, without being discolored or afiected in any way by the prod-' nets of combustion, for the reason that complete combustion occurring in the spaces at the top of the chambers there are no free particles of carbon or discoloring-gases in the products of combustionthat is, no such gases as would discolor ordinary articles of commerce, such as are usually burned or annealed in ovens.

It will be obvious that by the manipulation of various dampers and damper-plates used in my improved furnace the available areas for the intake of air, the escape of products of combustion, &c., can be regulated or controlled in such manner as may be demanded by varying conditions, such as the use of different kinds of coal, 850.; also, that the amount of water to be vaporized in the pans V and V can be regulated at will. I will also state that in ordinary practice a bed of fuel to the depth of about five feet or more is maintained in the firing'chamber and that the door 0' is closed all the time, with the exception of occasions when the ashes from the ash-pit are removed (about once everytwentyfour hours) or at such other times as it is desired to rake down the ashes from the gratebars.

I am aware that minor changes in the arrangement, construction, and combination of the several parts of my device can be made and substituted for those herein shown and described without in the least departing from the nature and principle of my invention.

I do not claim in this application the combination with a firing-chamber in which combustion of the fuel takes place slowly, a mixing-chamber for receiving the combustible gases resulting from the decomposition of fuel in-said firing-chamber, passages for ad mitting heated air to the mixing-chamber, and a combustion-chamber into which the heated air and combustible gases are directed in a burning state from the mixing-chamber, as the same is claimed in my former application, above referred to; but

What I do claim is 1. In a furnace the combination with walls which converge toward the lower portion, of grate-bars arranged in said lower portion, vaporizing-pans arranged in the lower front portion of said furnace, a supply-pipe for furnishing liquid to said pans, means for admitting air to support slow combustion in said furnace, and a charging-door in the upper-portion of the furnace through which fuel is fed; substantially as described.

2. The combination with the walls of a'furnace, of oppositely-placed tiles forming a top therefor, said tiles being recessed or cut away to provide passages for the gases escaping from said furnace; substantially as described.

3. The combination with the side walls of a furnace, of oppositely-placed tiles arranged thereon to form an arched top for said furnace, the inner edges of said tiles being recessed or cut away to provide passages for the gases escaping from said furnace, and a keystone or wedge arranged between said tiles; substantially as described.

4. The combination with a furnace, of a mixingchamber for receiving gases generated in said furnace, said mixing-chamber being formed in part by walls composed of fire-brick with spaces between and breaking joints with each other, through which spaces heated air is introduced into the mixing-chamber; substantially as described.

5. The combination with a furnace, of a mixing-chamber for receiving gases generated in the furnace, the walls of said mixing-chamber being provided with openings through which heated air passes into said mixing-chamber, and oppositely-placed tiles arranged in the upper portion of said mixingchamber, said tiles being provided with inwardly-extendingdeflecting projections; substantially as described.

6. The combination with a furnace, of a mixing-chamber for receiving gases generated in the furnace, the walls of said mixing-chamber being provided with openings through which heated air passes into said mixing-chamber, oppositely-placed tiles arranged in the upper portion of said mixingchamber, said tiles being provided with inwardly-extending deflecting projections, and tiles J arranged-above said last-mentioned tiles and provided with triangular-shaped projections in vertical alinement with said deflecting projections; substantially as described.

7. The combination with a furnace, of a mixing-chamber for receiving gases generated in the furnace, the walls of said mixing-chamber being provided with openings through which heated air passes into said mixing-chamber, oppositely-placed tiles arranged in the upper portion of said mixingchamber, said tiles being provided with inwardly-extending deflecting projections, tiles J arranged above said last-mentioned tiles and provided with triangular-shaped projections in vertical alinement with saiddeflecting projections, and a lintel supported by said triangular-shaped projections-and forming the roof of said mixing-chamber; substantially as described.

8. The combination with the Walls of a mixing-chamber, of tiles arranged thereon and provided with inwardly-extending deflecting projections, and a plurality of dampers guided in ways formed in said tiles; substantially as described.

9. The combination with the walls of a mixing-chamber, of tiles arranged thereon and provided with inwardly-extending deflecting projections, a plurality of dampers guided in ways formed in said tiles, a rod to which said dampers are connected, sheaves or pulleys supported above said rod,a counterbalancing-weight, and a flexible connection between said way and rod, said connection passing over said sheaves or pulleys; substantially as described.

10. The combination with a mixing-chamber, of tiles J arranged along the side walls thereof, said tiles being provided with inwardly-extending deflecting projections j, tiles J arranged above the tiles J and provided with triangular-shaped projections j, and a guiding-lip j, a lintel K supported by the projections j, and tiles L supported by the tiles J; substantially as described.

11. The combination with the furnace A, of the tiles D forming the top thereof, said tiles being provided with recesses cl" in their backs, of tiles G formed with recesses g re istering with said recesses d, intake-passages I I, a passage 11 for receiving the air from the passage 1 through a series of small openings 7?. connecting said two passages, the passages g leading from the passage H and the registering passages d discharging into a space F, a mixing-chamber arranged above the furnace A, and having its side wall formed of fire-brick with spaces between which connect the space F with the mixing-chamber E; substantially as described.

In testimony whereof I hereunto affix my signature, in the presence of two witnesses, this 9th day of May, 1900.

FREDERICK R. SELLMAN.

Witnesses:

WM. H. 800m, A. S. GRAY. 

